The universal unifier

No vocalisation is more universal (or unifying) than laughter. There are no language or cultural barriers – everyone everywhere understands the concept – and there’s no learning curve. “Babies don’t need to have seen or heard laughter to know how to do it,” says Sophie Scott, PhD, a professor of cognitive neuroscience at University College London and one of the world’s leading experts on laughter. But why do we laugh?
According to scientific studies, it’s not just corny jokes, funny photos or funny movies that elicit chuckles. In fact, humour isn’t even the main reason we laugh. Curious about the cause of our giggles and guffaws, we asked Scott to explain the science behind laughter, including the health benefits. This is guaranteed to make you want to laugh more every day.
What is laughter?

“Laughter is a nonverbal emotional expression,” Scott explains. “The emotion that we seem to be expressing with it is joy, but it’s a social joy that is primarily experienced with other people.”
The community aspect of joy is paramount to understanding the reasons we laugh. While people certainly can (and do) laugh when they are alone, they’re much less likely to than when they’re around other people. According to a scientific paper published in Trends in Cognitive Sciences, people are 30 times more likely to laugh if they are with someone else than if they are alone.
But it’s not something we do intentionally, at least not when it comes to the sort of genuine laughter that bubbles out of us. What’s more, there are times when we can’t help but laugh (and can’t stop), such as if we’re being tickled.
So what exactly is happening in the body when we laugh? Scott explains that laughter is a physiological response. When we laugh, the brain releases endorphins, which relax the whole body. Our facial muscles and respiratory system are both involved in laughter.
In other words, we’re hardwired for laughter. Everyone has the ability to laugh, even blind babies who have never seen laughter and deaf babies who have never heard it. Other mammals laugh too, including rats when they are tickled. “It’s likely that many species of animals laugh and we just don’t realise it because we don’t know what their laughter sounds like,” Scott says.
Why do we laugh?

Sure, you’ll snicker at silly dad jokes and funny pickup lines, but contrary to what many believe, finding something funny is not the only cause – or even the main cause – of those chuckles. So why do we laugh? There are four primary reasons, and they relate to our need for social connections, our desire to cloak our emotions, our uncontrollable bodily responses and, of course, our sense of humour.
For social connection
Scott points to social connection as the main driver of laughter. Yes, this plays an even bigger part in your belly laughs than hilarious jokes or funny songs.
“Most laughter happens as part of social interactions,” she says. Scientific research supports that. Remember the findings of the Trends in Cognitive Sciences paper? We’re 30 times more likely to laugh if we’re with someone else than if we’re alone. Another study found that people who don’t have many social relationships and live alone laugh less than those who have more social relationships and don’t live alone.
To mask our emotions
People don’t just laugh to express joy. Scott says that sometimes we laugh to mask other emotions. Feeling anger, anxiety or fear can lead to laughter (hence the term nervous laughter). Whether consciously or not, we may use laughter to manage these difficult emotions.
It’s a bodily response
Some people laugh as a response to bodily stimulation – namely, tickling. Scientists still don’t know exactly why tickling leads to laughter, but they do know it’s uncontrollable and involves the hypothalamus, the area of the brain that controls mood (along with body temperature, hunger and heart rate); the parietal operculum, an area involved in sensory, motor, autonomic and cognitive processing; the amygdala, where emotions are processed; and the right cerebellum, which is associated with language.
We find something humorous
It may not be the No. 1 reason we cackle uncontrollably, but finding something funny does make us laugh. Consider comedy movies. Many people find watching someone fall, an essential element of slapstick comedy, particularly humorous. Why do we laugh at this? According to a scientific paper published in Neuropsychologia, the facial expressions of the afflicted can cause us to laugh. When someone falls and looks bewildered, we find this funny.